摘要
以黄土高原南部两个长期定位试验（分别开始于1990和2003年）为研究对象,探讨了不同肥料处理对玉米根茬生物产量和养分累积的影响.于2011年10月玉米收获后采集0-20 cm土层不同施肥处理玉米根茬.结果表明：与不施肥及偏施N、NK、PK化肥相比,氮磷配施（NP）、氮磷钾平衡施肥（NPK）、有机无机配施（M1NPK、M2NPK）及化肥配合秸秆（SNPK）处理均显著提高了玉米根茬干质量.根茬固碳量及氮、磷、钾养分累积量在NP、NPK、M1NPK、M2NPK、SNPK处理显著高于不施肥和偏施N、NK、PK化肥处理,其中以有机无机配施处理效果最好.与不施氮肥（N0）相比,施氮120 kg N·hm^-2（N120）和240 kg N·hm^-2（N240）处理根茬干质量分别提高38%和45%,高量氮肥对根茬增量效果不显著.施用氮肥也显著提高了根茬碳、氮、磷、钾累积量.根茬可溶性有机碳、可溶性总氮含量在NP、NPK、M1NPK、M2NPK、SNPK及N120和N240处理中较高.氮磷钾平衡施肥、有机无机配施以及秸秆还田处理降低了根茬的纤维素、木质素含量.根茬C/N、木质素/N在CK、PK、N0处理间显著高于其他施肥处理.因此,氮磷配施、氮磷钾平衡施肥、有机无机配施及秸秆还田处理能够促进玉米根生长,提高营养成分含量,有利于土壤培肥和固碳.
Taking two long-term local field trials at the south edge of the Loess Plateau,which were found in 1990 and 2003,respectively,as test subjects,the effects of different fertilization practices on the maize root biomass and nutrient content were investigated in this paper. Maize roots in the0- 20 cm top soil post-maize harvest from the different fertilization practices were collected by hand in October 2011. The results showed that compared with control without fertilization and N,NK,or PK treatments,the NP,NPK,fertilizers plus manure（ M1 NPK and M2NPK） or plus straw return（ SNPK） treatments significantly increased the dry mass of maize root. The C,N,P and K contents in maize roots in the NP,NPK,M1 NPK,M2NPK and SNPK treatments were also significantly higher than those of control,especially in the NPK plus organic manure treatments（ M1 NPK and M2NPK） in the trial. Compared with the N fertilizer free treatment（ N0）,root biomass in the 120 kg N·hm- 2（ N120） and 240 kg N·hm- 2（ N240） fertilization treatments increased by 38% and 45%,respectively,but there was no significant difference between N120 and N240treatments. Nitrogen fertilizer application（ N120 and N240） also improved the C,N,P and K contents in maize root. The water soluble organic C and total soluble N contents of maize root in the NP,NPK,M1 NPK,M2NPK,SNPK and the N120 and N240treatments were greater than those of control and other treatments. Otherwise,the cellulose and lignin contents in maize roots declined in the NPK,M1 NPK,M2NPK,and SNPK treatments compared with other treatments. So the root C / N and lignin / N ratios in the control,PK and N0 treatments were significantly higher than those in the NP,NPK,M1 NPK,M2NPK and SNPK treatments. We concluded that the optimum fertilization（ e. g.,NP,NPK,MNPK and SNPK treatments） could increase maize root growth and nutrient content and improve soil fertility and carbon sequestration through root residue into soil.
出处
《应用生态学报》
CAS
CSCD
北大核心
2015年第8期2387-2396,共10页
Chinese Journal of Applied Ecology
基金
国家自然科学基金项目(31372137)
"十二五"国家科技支撑计划项目(2012BAD15B04)
高等学校学科创新引智计划项目(B12007)资助
关键词
长期施肥
氮肥水平
玉米根茬
干质量
养分累积
long-term fertilization
nitrogen application rate
maize root
dry mass
nutrient accumulation
